Apparatus for proportioning the flow of fluids



J. J. MAXON June 9, 1942.

APPARATUS FOR PROPORTIONING THE FLOW OF FLUIDS Filed Nov. 14, 1939 2Sheets-Sheet 1 .l. .l. m 9 oo 7- 6 5 A? Z] k N m m m v A w l A K v .7 T42 1 m N H mm 2 3 IN!!! 1 n7 3 0 F .l I 5 o 3 v. 2 2| v 6 J APPARATUS FORPROPORTIONING THE FLOW OF FLUIDS Filed Nov. 14, 1959 2 Sheets-Sheet 2FIG. 5

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d oHN J. MAX'QN Patented June 9, 1942 UNITED STATES PATENT OFFICEAPPARATUS FOR PROPORTIONING THE FLOW F FLUIDS John J. Maxon, Muncie,Ind., assignor to Maxon Premix Burner Company, Muncie,-Ind., a cor-Duration of Indiana Application November 14, 1939, Serial No. 364,377Claims. (Cl. 2773) This invention relates to improvements in appressure,This frictional resistance varies with paratus for proportioning theflow of fluids. each individual installation clue tothe fact thatExperience in the proportioning of gas and furnaces are not exactlyalike, and that inair, and in the proportioning of liquid fuelstallations of piping are not exactly alike either (either oil orliquefied gases) and air, for the 5 as to diameter or length, or as tothe number,

purpose of making a combustible fuel-air mixcharacter and arrangement ofelbows and other ture for use in industrial furnaces, ovens, andfittings. The effect of this frictional resistance, the like; hasbrought to attention certain factors like that of he internal furnacepressure above of how to obtain control of such fuel-air mixof the fuelinlet and of the air inlet in the pro ture so that a-uniformly eflicientor a uniformly portioning means. I

controlled furnace atmosphere, or both, may be For the reason that theeffectiveness of "the had. air inlet is less when the furnace isoperating One of these factors is internal furnace presat maximum firingrate, than when the burners sure. It is well known that if a relativelylarge are turned down low; and that therefore there amount of fuel isbeing burned in a furnace dur-- is more area at the air inlet at highfiring rates ing a predetermined length of time, the vents than isneeded proportionately; and for the for the spent gases become choked,thus tending further reason that there is no way to predeterto set upwithin the furnace a considerable posimine the proportional air inletarea until the tive pressure. And, on .the other hand, if in anequipment is installed on a furnace and started the same furnace andduring the same length of up under actual operating conditions, itbecomes time, a relatively small amount of fuel is being necessary tochange the gas-air fuel ratio,i in burned, the functioning of the ventsis normal, conformity with the internal furnace pressure,

-' ingly remain slight. Similarly, in a furnace to countered. In o herwo d the appar tus for,

so functioning as to carry off spent products of compared with thelowerresistance which pre-' combustion during the lowflring rates,without vails at reduced flring rates. choking, These resistancepressures act to retard the These facts teach that in furnacesgenerally, flow of the fluids through both the fuel inlet and there is atendency toward a building up of inthe air inlet, such action being ofgreater intencreased internal pressure when the burners sity upon theair flow than upon the flow of the therefor are operating at wide openposition; liquid or gaseous fuel. Hence it is found genand a tendency toa lowering of internal furerally that in an industrial burner systemwhen nace pressure when the burners are operated operating at highfiring rates; the effect of the at intermediate or lower firing rates.This 40 internal furnace pressure is to cause propor-' changing internalpressure has a direct bearing tionally less air to enter the furnacethrough the upon the performance of all industrial burner burners thanis able to enter against the lower systems regardless of the meansemployed for internal furnace pressure prevailing at reduced measuringout the quantities of fuel and the firing rates. Thus there is aninherent tendquantities of air for the mixture thereof. ency in allknown industrial burner systems to Another of the factors above referredto, is produce a too rich" fire at high firing rates, frictionalresistance. By frictional resistance, is (that is to say, a type offirein which there is meant, resistance that is present in the pipes orinsufiicient volume of air to complete combustion pipe lines whichconduct the gas and air to the of fuel) thereby leading to, ineflicientoperation. burner nozzles through which the fuel mixture The conditionjust mentioned may be overis burned. This resistance increases as thefiring come by changing an adjustment on valves of rate goes up, and itdecreases as the firing rate proportioning devices hitherto devised andwell is diminished. In these instances the influence known, so that thearea of the air inlet is inon the burner system is much the same as thecreased to admit slightly more air and thus to influence which isincident to internal furnace restore the mixture proportions suitablefor producing the desired furnace atmosphere or combustion efficiency.It is well known however, that when such an adjustment is resorted to-soas to bring the proportions of the fuel mixture elements into desiredbalance at a high firing rate-the fire becomes lean" or oxidizing assoon as the firing rate is reduced. This effect is incident to theadmittance of a too-high volume of air against the lowered internalfurnace pressures or the lowered resistance conditions that prevail whenburners are: operated at reduced firing rate.

It is also well known that adjusting devices are also provided inproportioning apparatus as hitherto devised, whereby alteration of thearea of the fuel inlet may be had. However, in. all

prior apparatus of the kind referred to, the predetermined and fixedfuel-air ratio is unchanged. Whereas, by the use of. such prior devices,compensation may be had for variables met with in furnace operation,such as change in the B. t. u. value of fuel; change in the overallcharacter of furnace atmosphere (such change being sometimesnecessitated by a change in the type of work being handled through thefurnace or oven) and change in the basic or main pressure at which fuelor air is supplied to the proportioning device; (as in instances whereina furnace with burners operating on compressed air is modified so as tobe handled with burners operating on air supplied by a low pressure fan)it is believed that no proportioning apparatus has hitherto beendeveloped to compensate for the variables. with which the presentinvention has to do, and which said variables are again referred tobriefly, as follows;

Changes in internal furnace pressure caused by increase or decrease infiring rate of the burners.

Changes in frictional resistance of the air or fuel manifold piping(caused by increase or decrease of the rate of flow of fluids throughthese headers).

Changes in pressure at which combustion air is supplied up to theproportioning apparatus (that is, if furnace is equipped with blower orfan, and in which instance the pressure of the air supply will tend toweaken slightly as the firing rate increases), and

Changes in pressure of fuel supply up to the proportioning apparatus(caused by tendency of gas pressure or oil pressure to drop slightly asthe firing rate is increased).

To provide compensation for all variables met with in burner systems forfurnace or oven operations, inclusive of the variables lastly abovementioned, suchcompensation being regardless of the type of mixerthrough which the proportioned fluids are to. be confined and used, myidea is to afford means whereby to adjust the proportions of the twofluids (that is-to adjust the fuel-air ratio) at and to maintain saidadjustment for any point in the capacity range of the burner system.

Accordingly, the object of my invention, broadly stated, is to providean apparatus afford: ing facility whereby to vary the volume of inlet ofair as received from a supply source at any pressure, and to vary thevolume of the inlet of fuel as received from a supply source at anypressure, and to modify the proportioning so obtained, at and toestablish such modification for different stages of the feed flow of theproportioned air and fuel; by such facility, the combustible mixtureultimately resultant from said proportioning, being of consistency whichis dictated by the conditions under which the burner system and furnaceor oven are operated.

The above stated general object, as well as other and more specific aimsof my invention which will presently be apparent, are accomplished by,and my invention is embodied in the new construction, combination andarrangement of parts described in the following specification, andillustrated in the accompanying drawings. The different parts of theinvention are identified by suitable characters of reference applied tothem in the several views in the drawings, in which- Figure 1 is a frontview .of my new fluid-flowproportioning apparatus, a portion of coverplate being broken away.

Figure 2 is a side view, taken in the direction of arrow 2 in Figure 1,a portion of the air-inlet flange fitting being broken away.

Figure 3 is a side view of Figure 1, in the direction of arrow 3 inFigure 1, a portion of the cover plate, and a portion of the armstructure which is coordinated with the air inlet gate arm, and aportion of the flow discharge fitting being broken away.

Figure 4 is a vertical cross section view taken on the broken line 4-4,and in the direction of arrow 4 in Figure 1.

Figure 5 is a top plan view of Figure 1, taken in the direction of arrow5 in Figure 1; cover plate 10 being removed.

Figure 6 is a top plan view of the gate arm detached, a portion thereofbeing broken away and disclosing to view the resilient cam strip, and aportion of the latter being broken away, disclosing to view the curvedslot underneath same.

Figure 7 is a sectional top plan view taken on the broken line 1-1, andin the direction of arrow 1 in Figure 1.

Figure 8 is a diagrammatic view showing the gate valve at half-onposition.

Figure 9 is a diagrammatic view showing the gate valve at on position.

Figure 10 is a detachedvertical sectional view on the broken line ii-"i0, in the direction of arrow I0 in Figure 5.

The meaning of the word gas as herein occurring, is inclusive of liquidfuel. This fuel may be liquefied gas of any one of the many kinds knownand widely used, and/or oil.

By the term "combustible mixture as used herein, is meant the combinedvolumes of gas and of the air used for the combustion thereof after suchvolumes will have passed from the discharge openings of my new andimproved apparatus described herein. 3

Cast metal casing structure I! embodies a vertical bore I3 at the top ofwhich is secured a plate 14 provided with a circular opening I. Openingswhich communicate with said bore II from opposite sides thereof, aredesignated as air inlet [8, and air outlet iii. A conventional flangefitting 20 accommodates air inlet pipe 2|. A hollow cylindrical gate 22and which is rotatively retained in the said bore l3 embodies a circularboss which is received in the bore I! of the said top plate It. The saidgate is provided with apertures 23 and 24 so positioned, that with aturn of the gate through one fourth of a revolution its status ischanged from closed position to open position, and vice versa. Axialshaft 21 which is made fast, to said gate as by being threaded thereinand secured by a'nut 28; and

by a stud pin which projects from the top of said gate, constitutes apower transmitting connection and it will presently receive furtherreference.

Embodied by said casing, and located closely adjacent to the said boreI3 is a cavity 3|. At an open side thereof a plate 32 is secured, as bycap screws 33. An opening from said cavity and which is located adjacentto said air outlet I9, I designate as gas outlet 34. Side face 35 of thecasing is adapted to have secured thereto,

a hollow fitting 36 to span said air outlet l9 and the said gas outlet34, and to which may be attached a delivery or conducting conduit (notshown) of any desired type. Threaded opening 31 in the side plate 32 andwhich is adapted to receive gas inlet pipe 39 communicates with theinterior of an entry box 38 which is integrated with said side plate, asillustrated in Figure 4.

A fluted flanged valve head 40 which is retained loosely in a bore inthe top side of the said entry box, and which is seated as at 4|, has astem 42 which is received in the central bore of an abutment head 43. v

This abutment head is screwed to sealed position in the bottom side ofsaid entry box. A helical spring 45 whose one end bears against theshank of said abutment head has its other end impinged against the saidvalve head 40, the latter thereby being retained yieldingly in itsclosed position as indicated in Figure 4.

Loose in the bore of a bushing 46, and which said bushing in turn isslidingly retained in a bore 44 therefor provided in the casing atposition immediately above the valve head 40, is a push rod 41. Thispush rod, made preferably of non-corrosive metal, is of such length thatwith its lower end in engagement with the said valve head 40, its otherend extends a predetermined distance above said bushing. Packing in saidbore 44 constitutes a closure at said push rod and to prevent egress ofgas from cavity 3|. A helical spring 5| which is disposed within acounterbore of the said bushing 46, and upon a washer 52 that reposes onsaid packing, urges the said bushing upwardly, and for the purposepresently to be set forth.

A member which consists of a segmental plate 53 having a hub 54 providedwith a bore 55, I designate as an arm structure. For moving of this armstructure. a projecting member 68 available as a handle connection towhich mechanical means (not shown) may be attached, is provided. In thebottom face of said hub is a recess 56. A slot 51 of curvature struckfrom the axis of said hub is so located, that upon lowering the said armstructure to its operative position (see Figure 4) the shaft 21 willhave been received in the bore 55, and the stud pin 30 will have beenreceived in the recess 56 of the said hub, the push rod 41 will havebeen received in the slot 51, and the bottom face of the said armstructure at slotted portion thereof, will have come into engagementwith the top face of the aforesaid bushing 46.

Upon screwing the nut 58 on the upper portion of said shaft 21 .totightened engagement with the said hub, the said arm structure will havebeen securely united with the said gate 22, the said shaft 21, stud pin30 and nut 58 constituting power transmitting devices interconnectingthe arm structure and the gate, whereby upon a movement of the armstructure, there is a corresponding movement of the gate.

At the top surface of the casing is an index point Z and which islocated in registration with a line bisecting the center of said pushrod 41.

In the marginal top portion 65 of said arm structure, and which said topportion is of curvature the same as slot 51, threaded adjusting pins 61are arranged in succesive order, as shown in Figures 1 and 5. They aredesignated by numerals-reading from left to rightnamely, 0, I, 2, 3, 4,5, 6, 1, 8, 9, I0 and II. Each of these pins is individually adjustableby the use of a suitable implement such as a screw driver, and each iscapable of being stayed at the position to which it is adjusted, as by alock screw 69.

It is by the adjusting vertically, of these pins, carried as they are,in relation to the push rod; and each, constituting, as it does, a powertransmitting element to actuate the push rod when brought into coactingrelation with the latter; that a determinate measure 'of the range ofdownward movement of the push rod (and therefore a determinate measureof the extent of opening movement of the gas valve) may be had for andin relation to any one of the multiple settings to which the air gatemay be moved, such measure being independent of the measure had at anyone, and all other of said multiple settings.

To facilitate the passing of the pins into the zone of engagingregistration with said push rod, and to contribute to ease in handlingthe arm structure in its moving of the air gate I provide the parts asfollows; A body piece 63 for manual use, or as a secured at its baseportion as by cap screws 66 to the part 53 of the said arm structure,embodies marginal portion which is of curvature the same as thecurvature of said slot 51. Said body piece is of formation in crosssection, as shown in Figure 10, to provide a curved cavity 64. A curvedstrip 6| made of flexible material such as laminated steel and ofsuitably light gauge, has medial arm portion secured, as by cap screws,to the underside of the base portion of the part 63. This strip ispoised within said cavity 64 and immediately underneath the se ries ofpins, and it is of length to span the reach of the curved slot 51.

medial arm portion, the urge of the strip is upwardly, and thereforetoward the bottoms of said pins, said bottoms being rounded as indicatedin the drawings. Against the underside of the strip 6|, the push rod 41(urged upwardly and toward said pins by the spring 45) impinges. Saidstrip, yielding as it does, in the portion thereof immediately at thepush rod and adjacent pin, it constitutes a practicable bridging tofacilitate the passing of the pin to engagement with the said push rod.Pressure of spring 5| against bushing 46, holds the latter against theunderside of part 53, thereby staying the arm structure.

In readiness to be operated, the invention with its several parts intheir correlated positions, appears as shown in the drawings, the armstructure having been moved in the direction of the arrow off, to theextreme end of its stroke, the indicator numeral 0 having been broughtto the zero point Z. The air inlet It? now is closed. The gas valve head40 is in the closed position.

The arm structure, by the handle 68 is now moved in the direction ofarrow on, see Figure 5) bringing the indicator numeral 1 to index Z. Pinat I is then adjusted to afford the desired measure of opening at gasvalve 40. When tests at the furnace (not shown) indicate that By theaction of said the proper amount of gas volume has been obtained withrelation to the volume of air which is being admitted at the gate at airinlet I 8, the adjusting pin l is stayed by tightening the lock screw69. Now the handle 68 is again moved in the direction of arrow onbringing the indicator numeral 2 to the index Z. Pin 2 is then adjustedso as to afford the desired measure of opening of the gas inlet valve40. When the tests continued at the furnace indicate that the properratio of gas to the air, as the latter is admitted at I8, is had (at thestage wherein the pin 2 is at index Z) its lock screw is tightened. Thehandle 68 is again moved in the direction of arrow on, the pin 3 beingbrought to index Z and then adjusted to and made fast in desiredposition. With each succeeding shift of the said arm structure, there isthe adjusting and staying of the pins at 4, 5, 6, I, 8, 9, l and H intheir successive order.

It will be understood that by the urge of spring 48 against the valvehead 40, the push rod 41 is held constantly pressed upwardly against theface of the flexible strip GI, and that the latter affords a suitablebridging tosmoothly ease the passing'by the pins, one after another, totheir respectivepositions as related to the top of the said push rod.

A cover plate in fitted connection with the arm structure as by a capnut ll applied to the end of gate shaft 21, constitutes a protectiveshield for the said arm structure and the adjusting pins 61.

An annular ring shaped plate 12 of predetermined internal diameter andwhich is made fast to the side of the casing, as by cap screws 13,determines the diameter of, and it centers the discharge flow of theproportioned streams of air and gas.

The invention lends itself to use in connection with automatic controlfacilities of any conventional type. In such instance, a crank member(not shown) is substituted for the handle 68.

The invention renders practicable the supplying of air and gas volumesin proportions suitable for combustible mixtures intended for bumersystems generally, and whether the point of delivery of the proportionedvolumes is adjacent to, or is remote from, the locus of the apparatus.It lends itself tonin'stallations whereby the gasair proportions whichit supplies, may be discharged under pressure into the piping system andmay be burned from one nozzle or from a plurality of nozzles. Either theopen port, or the sealed port method of firing may be practiced. Linetype nozzles also may be used.

The utility of my invention and the advantages accomplished by itspractice are obvious. When tests of the combustible mixture (saidmixture being constituted at the furnace (not shown) by suitableintermingling of the gas and air streams flowing from the gas outlet 34and the air inlet l9 respectively) will have indicated the nature ofchange in the proportions of said streams necessary to compensate forsuch specific. atmosphere conditions in the furnace as may have beenencountered, variation of the volume of gas flow may be had andmaintained at any stage in the capacity range of firing. Or, in otherwords,

- at any setting of the air inlet gate between its extreme positions ofoif" and on. When the apparatus will have been set in conformity withthe furnace conditions for which it is adjusted, the firing rate isapparent by observing the position at which the said arm structure isset.

Included in the class of plant organizations wherein the problems ofobtaining efllcient burner system operation and efficient combustion arecommon, are annealing furnaces, forge furnaces, furnaces for heattreating, steel mill furnaces, and reverberatory melting furnaces. Inall of these, my invention is of utility in making possible theobtaining of proportioning of the elements going into the make-up of therequired combustible mixtures whereby compensation is had as dictated bylocal conditions.

In the embodiment of my invention as herein illustrated and described,the amount of machine work involved is relatively small; the differentparts are capable of being economically assembled and interconnected,and the apparatus in its entirety is close built and substantial, and isnot liable to get out of order. Access may be readily had to theinterior thereof when necessary for inspection and cleaning or forrenewals; and the device throughout is capable of bein modified as todetails to meet capacities of all ranges, and'various installationsconditions.

Whereas I have shown and described my invention in form embodyingstructure and details of preferred, formation and arrangement, it willbe understood that modifications may be made in the details ofconstruction, form, and arrangement of the several parts, within thescope of the invention as it is defined in the appended claims, withoutdeparting from the spirit or principle of the invention or sacrificingany of its advantages.

What I claim as my invention is:

1. Apparatus for proportioning the flow of air and fuel to industrialburner systems, comprisarate and independent compartment, said entry boxhaving fuel inlet and outlet connections and a stemmed valve, acompression spring constantly urging said stemmed valve towards closedposition, a push rod extending through a packing gland in the wall ofsaid entry box and aligned for direct engagement with said stemmed valveand operable to open same in opposition to the urge of said compressionspring, means for. actuating the push rod simultaneously with the movingof said arm structure and for varying at different positions of the gatethe ratio between the extents of opening of said gate and stemmed valve,said means including a series of individually adjustable threaded pinscarried by the said arm structure and so located that upon movement ofthe latter through its range of positions, the threaded pins will bebrought successively into engagement with the push rod, each in its turnthus actuating the latter, a fiexible strip carried by said armstructure and interposed betwen the push rod and the threaded pins, tofacilitate their said engagement, whereby at each of the multiplepositions to which said arm structure is moved, the flow of fuel andflow of air are proportioned one to the other, and an air-fuel ratiosprevailing at other positions, is established and maintained.

2. Apparatus of the kind described, comprising a valve for the air, anda valve for the fuel, an arm structure operable to move the air valve, aspring to urge the fuel valve toward closed position, a push rod carriedby the fuel valve and operable to resist said urge, successivelyarranged pins carried by said arm structure in line with said push rod,each being individually adjustable with relation to said push rod, meansto secure each of said pins in the position to which the latter isadjusted, and a flexible bridging strip fixedly secured to said armstructure and carried thereby in position between said successivelyarranged pins and the said push rod.

3. Apparatus of the kind described for proportioning the flow of air,and the flow of fuel, to industrial burner systems and the like,comprising a casing structure having a cylindrical bore and beingprovided with an open compartment adjacent to said bore, and each ofopposite sides of said bore having an opening therein, one for ingressof the air to, and the other for the egress of the air from the saidcasing structure, and there being an outlet from said compartment, agate iournaled in said bore and having ports so arranged that with aturn of the gate through ninety degrees in one direction the ports aretransposed from closed position to open position, and when said gate ismoved through ninety degrees in ,the opposite direction the said portsare transposed from open position to closed position, a segmental armstructure coordinated with and operable to move the gate from one to theother of its extreme positions, an entry box associated with andconstituting a closure of said compartment and which said entry box isprovided with a fuel inlet, a valve for the fuel inlet, a push rodengaged with said fuel valve and extended through the wall of thecasingstructure, spaced threaded pins carried by and protruding from thecircumferential marginal portion of the said arm structure and which arecapable of being screwed to and fastened at adjusted positions, packingat the said push rod, a brake device to yieldingly stay the said armstructure at any of the positions to which it is moved, and an arcuateflexiblev strip fixedly secured to and carried by the said arm structureat a plane between the push rod and the said pins.

4. Apparatus of the kind described for proportioning the flow of air andthe flow of fuel to industrial burner systems and the like, comprising acasing structure having a cylindrical bore and there being an opencompartment within said casing, and each of opposite sides of said borehaving an opening therein, one for ingress of air to, and one for egressof air from the said casing structure, and there being an outlet fromsaid compartment, a gate Journaled in said bore and having ports soarranged that with a turn of the gate through ninety degrees in onedirection the ports are transposed from closed position to openposition, and when the gate is moved through ninety degrees in theopposite direction the said ports are transposed from open position toclosed position, an entry box associated with and constituting a closureof said compartment and which said entry box is provided with a fuelinlet, a valve for the fuel inlet, a push rod engaged with said fuelvalve and extended through the wall of the casing structure, a rotatablymounted arm structure, power transmitting devices interconnecting thearm structure and said gate, means to constantly urge said fuel valvetoward closed position, a brake device to yieldingly stay the said armstructure at any of the positions to which it may be moved, a flexiblestrip fixedly secured to and carried by said arm structure inregistration with said push rod. and a series of individually adiustablepins carried by said arm structure, and against the ends of which saidpins the said flexible strip is urged. 4

5. In apparatus of the kind described, the combination of a casinghaving an air inlet and an air outlet, a gate device to regulate theamount of air admitted to and discharged from said casing, a casinghaving a fuel inlet and a fuel outlet, a stemmed valve for the fuelinlet, a spring to urge the fuel valve closed, a push rod in engagementwith said stemmed valve and operable to move said stemmed valve inopposition to said urge, a rotatably mounted arm structure operablebetween two positions and which is adapted for actuation either manuallyor mechanically, power transmitting devices interconnecting the said armstructure and the said gate whereby upon rotative movement of the armstructure there is rotative movement of the gate, means interactingbetween the arm structure and the push rod to actuate the lattersimultaneously with the actuation of said arm structure, said meansconsisting of a series of protruding pins carried by the arm structure,each of said pins being adjustable, a set screw to lock each of the pinsat the position to which it is adjusted, and a flexible strip fixedlysecured to and carried by said arm structure in position between thesaid pins and the said push rod.

'JOHN J. MAXON.

